/*
+ * This is a derivative of the similarly named class in the YUI Library.
+ * The original license:
+ * Copyright (c) 2006, Yahoo! Inc. All rights reserved.
+ * Code licensed under the BSD License:
+ * http://developer.yahoo.net/yui/license.txt
+ */
+
+/**
+ * @class Ext.dd.DDProxy
+ * A DragDrop implementation that inserts an empty, bordered div into
+ * the document that follows the cursor during drag operations. At the time of
+ * the click, the frame div is resized to the dimensions of the linked html
+ * element, and moved to the exact location of the linked element.
+ *
+ * References to the "frame" element refer to the single proxy element that
+ * was created to be dragged in place of all DDProxy elements on the
+ * page.
+ *
+ * @extends Ext.dd.DD
+ * @constructor
+ * @param {String} id the id of the linked html element
+ * @param {String} sGroup the group of related DragDrop objects
+ * @param {object} config an object containing configurable attributes
+ * Valid properties for DDProxy in addition to those in DragDrop:
+ * resizeFrame, centerFrame, dragElId
+ */
+Ext.define('Ext.dd.DDProxy', {
+ extend: 'Ext.dd.DD',
+
+ statics: {
+ /**
+ * The default drag frame div id
+ * @property Ext.dd.DDProxy.dragElId
+ * @type String
+ * @static
+ */
+ dragElId: "ygddfdiv"
+ },
+
+ constructor: function(id, sGroup, config) {
+ if (id) {
+ this.init(id, sGroup, config);
+ this.initFrame();
+ }
+ },
+
+ /**
+ * By default we resize the drag frame to be the same size as the element
+ * we want to drag (this is to get the frame effect). We can turn it off
+ * if we want a different behavior.
+ * @property resizeFrame
+ * @type boolean
+ */
+ resizeFrame: true,
+
+ /**
+ * By default the frame is positioned exactly where the drag element is, so
+ * we use the cursor offset provided by Ext.dd.DD. Another option that works only if
+ * you do not have constraints on the obj is to have the drag frame centered
+ * around the cursor. Set centerFrame to true for this effect.
+ * @property centerFrame
+ * @type boolean
+ */
+ centerFrame: false,
+
+ /**
+ * Creates the proxy element if it does not yet exist
+ * @method createFrame
+ */
+ createFrame: function() {
+ var self = this;
+ var body = document.body;
+
+ if (!body || !body.firstChild) {
+ setTimeout( function() { self.createFrame(); }, 50 );
+ return;
+ }
+
+ var div = this.getDragEl();
+
+ if (!div) {
+ div = document.createElement("div");
+ div.id = this.dragElId;
+ var s = div.style;
+
+ s.position = "absolute";
+ s.visibility = "hidden";
+ s.cursor = "move";
+ s.border = "2px solid #aaa";
+ s.zIndex = 999;
+
+ // appendChild can blow up IE if invoked prior to the window load event
+ // while rendering a table. It is possible there are other scenarios
+ // that would cause this to happen as well.
+ body.insertBefore(div, body.firstChild);
+ }
+ },
+
+ /**
+ * Initialization for the drag frame element. Must be called in the
+ * constructor of all subclasses
+ * @method initFrame
+ */
+ initFrame: function() {
+ this.createFrame();
+ },
+
+ applyConfig: function() {
+ this.callParent();
+
+ this.resizeFrame = (this.config.resizeFrame !== false);
+ this.centerFrame = (this.config.centerFrame);
+ this.setDragElId(this.config.dragElId || Ext.dd.DDProxy.dragElId);
+ },
+
+ /**
+ * Resizes the drag frame to the dimensions of the clicked object, positions
+ * it over the object, and finally displays it
+ * @method showFrame
+ * @param {int} iPageX X click position
+ * @param {int} iPageY Y click position
+ * @private
+ */
+ showFrame: function(iPageX, iPageY) {
+ var el = this.getEl();
+ var dragEl = this.getDragEl();
+ var s = dragEl.style;
+
+ this._resizeProxy();
+
+ if (this.centerFrame) {
+ this.setDelta( Math.round(parseInt(s.width, 10)/2),
+ Math.round(parseInt(s.height, 10)/2) );
+ }
+
+ this.setDragElPos(iPageX, iPageY);
+
+ Ext.fly(dragEl).show();
+ },
+
+ /**
+ * The proxy is automatically resized to the dimensions of the linked
+ * element when a drag is initiated, unless resizeFrame is set to false
+ * @method _resizeProxy
+ * @private
+ */
+ _resizeProxy: function() {
+ if (this.resizeFrame) {
+ var el = this.getEl();
+ Ext.fly(this.getDragEl()).setSize(el.offsetWidth, el.offsetHeight);
+ }
+ },
+
+ // overrides Ext.dd.DragDrop
+ b4MouseDown: function(e) {
+ var x = e.getPageX();
+ var y = e.getPageY();
+ this.autoOffset(x, y);
+ this.setDragElPos(x, y);
+ },
+
+ // overrides Ext.dd.DragDrop
+ b4StartDrag: function(x, y) {
+ // show the drag frame
+ this.showFrame(x, y);
+ },
+
+ // overrides Ext.dd.DragDrop
+ b4EndDrag: function(e) {
+ Ext.fly(this.getDragEl()).hide();
+ },
+
+ // overrides Ext.dd.DragDrop
+ // By default we try to move the element to the last location of the frame.
+ // This is so that the default behavior mirrors that of Ext.dd.DD.
+ endDrag: function(e) {
+
+ var lel = this.getEl();
+ var del = this.getDragEl();
+
+ // Show the drag frame briefly so we can get its position
+ del.style.visibility = "";
+
+ this.beforeMove();
+ // Hide the linked element before the move to get around a Safari
+ // rendering bug.
+ lel.style.visibility = "hidden";
+ Ext.dd.DDM.moveToEl(lel, del);
+ del.style.visibility = "hidden";
+ lel.style.visibility = "";
+
+ this.afterDrag();
+ },
+
+ beforeMove : function(){
+
+ },
+
+ afterDrag : function(){
+
+ },
+
+ toString: function() {
+ return ("DDProxy " + this.id);
+ }
+
+});
+